It was partly conditioned on geographical continuity without being necessarily caused thereby, and was wholly independent of any uniformity of climate.

The association was in the beginning largely a matter of convenience or a matter of habit.

Those associations endured which proved under stress of historical vicissitudes to be worthy of endurance.

The longer any particular association endured, the more firm it became in political structure and the more definite in policy.

Its citizens became accustomed to association one with another, and they became accustomed to those political and social forms which supplied the machinery of joint action.